1. Field of the Invention
The present invention relates to lumen sizers, and more particularly relates to lumen sizers having a sizing projection at either end of a central hand-held portion to facilitate sizing of organs during a surgical procedure such as anastomosis.
2. Description of the Related Art
Surgical anastomosis of organs has, in recent years, increasingly involved the use of surgical staplers to join the ends of the organs. Such staplers are described in commonly-owned U.S. Pat. Nos. 5,119,983, 5,112,156, 4,752,024, and 4,603,693. Because these anastomosis staplers provide a circumferential ring of staples about the periphery of the organ wall, it is necessary to ensure that the size of the stapler head closely matches the lumen size of the organ. Thus, the lumen size must be accurately measured for selection of the appropriately-sized instrument.
Previously, devices have been introduced to size the lumens of a variety of anatomical structures during surgical procedures. U.S. Pat. No. 5,042,161 to Hodge relates to an intravascular sizing gauge having a series of sizing cylinders disposed at each end of a central holding section. Each cylinder has a diameter of a given size with cylinders having progressively decreasing diameters towards the insertion end of the instrument. The surgeon must check the instrument to read the numerical size on the gauge to ascertain correct fit of an instrument in the lumen.
U.S. Pat. No. 3,740,779 to Rubricuis relates to a surgical instrument for measuring the circumferential diameter of an orifice or mouth of a tube or duct. The instrument comprises a single cone-shaped end having a series of metered markings. The cone is inserted into the orifice until the appropriate size is reached. Like the Hodge device, the Rubricuis instrument suffers from the disadvantage that the size must be read by the surgeon to ascertain proper lumen size.
U.S. Pat. No. 3,938,504 to Dickinson, III et al. relates to a method for measuring the dimensions of the vagina, specifically, the effective diameter of the vaginal sphincter muscle of an animal. The instrument has a single, blunt-ended cone portion mounted over the end of an elongate handle. Travelling from the blunt end of the cone portion towards the handle portion, the cone portion gradually increases in diameter, reaching a maximum diameter at an intermediate ring, and then gradually decreases in diameter. This instrument has a only single insertion end and several different materials are used in the construction of the instrument. Further, the intermediate ring provides only a small surface area of maximum diameter which can lead to inaccurate measurements.
The information booklet for Auto Suture.RTM. S-EEA Sizers.TM. describes a reusable sizing instrument having only a single insertion end.
Thus, a need exists in the art for a surgical instrument which can quickly and accurately indicate the lumen size of an organ during surgical procedures. The need further exists for a surgical instrument having multiple sizing portions which can safely be inserted into a lumen without tissue trauma or excessive stretching of the lumen opening. Such an instrument could be used to provide an indication of lumen size to determine the size selection of a surgical instrument or prosthetic device.